脱硝系统SCR催化剂局部磨损原理分析和优化改造

Analysis and Optimization of SCR Catalyst Partial Wear Principle in Denitration System

采用气固两相流数值模拟和理论分析相结合的方式,对某电厂660 MW机组锅炉选择性催化还原(SCR)烟气脱硝系统内部气固两相流场进行测试计算,分析了该脱硝系统上层催化剂在靠近前墙第一列区域磨损比较严重的原因,结果表明,催化剂磨损与其上方的气固两相流场和飞灰颗粒浓度分布有直接关系。原脱硝装置设计不尽合理造成高质量浓度、大粒径的飞灰颗粒被带到催化剂入口断面的近锅炉侧,从而造成催化剂近锅炉侧的磨损。提出导流板优化改造合理方案对脱硝装置进行了改造,解决了催化剂局部严重磨损问题。

The gas-solid two-phase flow field in a 660 MW Boiler selective catalytic reduction(SCR) flue gas denitration system of a power plant was measured and calculated by means of numerical simulation of gas-solid two-phase flow and theoretical analysis. The reason why the upper catalyst of the denitration system was seriously worn near the first row of front wall was analyzed The results show that the catalyst wear is directly related to the gas-solid two-phase flow field above the catalyst and the concentration distribution of fly ash particles The unreasonable design of the original denitration device caused the fly ash particles with high mass concentration and large particle size to be brought to the boiler side of the catalyst inlet section,resulting in the wear of the catalyst near the boiler side. A reasonable scheme for optimizing the deflector was put forward. The denitration unit was reformed, and the problem of severe local wear of catalyst was solved.